Discussion
QBee said:
I am slightly surprised that Powers warrant your engine rebuild with 18psi of turbo boost. Was the turbo on at the time, and did he fit special pistons etc ?
It only goes up to 18 for a very, very brief moment so most of the time when giving it the beans its around 10 for longer moments if you follow my drift. But you accelerate so fast and change gear that the boost is only on for brief moments really. I don't track the car so it is unstressed almost all the time.Powers warrant their straight six rebuilds for 100,000 miles which tells me they are the best in the business. That's why I chose them. The warranty on the engine was only given if they fully rebuilt it. They used standard parts, nothing fancy. But the whole cost was over £12,000. So, if there was a warranty claim, I think they've more than covered it in their price.
Also, Dom was made aware of my health concerns and was absolutely fantastic about everything. That's why I wouldn't go anywhere else.
PhilH42 said:
N7GTX said:
I have been tempted by trying a long lasting iridium plug (60k service interval on some Toyota) but 2 things stopped me.
1. This thread prompted me to contact NGK technical for advice and they have responded on here. Basically, you can use the iridium 6 on most normal or moderately modified engines. On heavily modified they said stay with the old recessed 7.
2. To prevent detonation at high boost I must use Shell Nitro, BP Ultimate or a minimum of 98 octane fuel (no knock sensors) at a current price of around £1.25 a litre
Oh, and the price of a Powers rebuild will make your eyes water so I'll bottle out and stick with the old plugs.
Totally understand your stance and I'd agree its probably a very sensible option in your circumstances but it does make me wonder what margin is put in there! In my experience (not specifically cars) everything now is very over engineered out of fear of litigation and I think that clouds the reality. I'm not doubting the experts advice but do you not cross the road ever again in case you get knocked over by a bus....I mean what's the real world risk of it actually happening and thats what I'd like to know to make an informed choice? It will happen to someone it always does but maybe the risk can be mitigated with more frequent change intervals and definitive boost or modification guidelines. 1. This thread prompted me to contact NGK technical for advice and they have responded on here. Basically, you can use the iridium 6 on most normal or moderately modified engines. On heavily modified they said stay with the old recessed 7.
2. To prevent detonation at high boost I must use Shell Nitro, BP Ultimate or a minimum of 98 octane fuel (no knock sensors) at a current price of around £1.25 a litre
Oh, and the price of a Powers rebuild will make your eyes water so I'll bottle out and stick with the old plugs.All this is not worth the punt of course unless you notice real everyday improvements.
Oh and bloody bad luck with the prang, no shame with some people, hope you manage to nail the *uck** to the wall.
Edited by PhilH42 on Wednesday 13th September 09:24
One thing NGK did say was that running bigger boost such as 10 psi or more then they would recommend using 8s particularly if on a track and even 9s if under extreme conditions. I don't track so they said the 7s were ideal. I've changed many iridium plugs on all sorts of cars and after 40, 50 or 60,000 miles they still look brand new.
Edited by N7GTX on Wednesday 13th September 11:12
I've been shot down for promoting the use of fine wire type plugs in the past so rather than get into another stupid forum spat lets instead look at what all the big car manufactures specify for their modern engines, and lets take it a step further by looking at what they put in their turbo engines as this is where a plug will see most stress. If the car makers specify a plug for an engine with forced induction you can be sure it'll be way over specified for a naturally aspirated engine.
The general answer is pretty much exclusively all manufactures have switched to a fine wire type plug, so to say this type of plug is unsuitable for old Rover (even a turbo charged Rover V8) is absolutely laughable.
Modern turbo charged engines are typically four cylinder and create a lot of heat, they put their spark plugs under way more stress than any Rover V8 would (even one running boost), however.... the heat range does remain as critical as ever, to reinforce this evidence lets look at the turbo charged Mk7 Golf GTI which is a good example to demonstrate my point.
The turbo charged Mk7 Golf GTI runs 14psi peak boost, the compression ratio of this modern four cylinder engine is 9.6:1, obviously the engine runs knock control pulling both timing and boost at the early onset of detonation, the engine is factory mapped to run 95Ron but VW do recommend premium grade fuel (97Ron in the UK) the engine management system will learn and adapt as it builds data, don't forget this engine in the US market must tolerate their 93Ron fuel all be it on a slightly different map.
This 2.0L inline four cylinder 16V turbocharged/intercooled engine makes 220hp at 4,700rpm and 258ft/lbs of torque at just 1,500rpm, 14psi spread over just 4 cylinders is a very different thing to 14psi shared across 8 cylinders, if we consider individual cylinder loads/pressures the turbo charged Mk7 Golf GTI must tolerate it would be the same as a V8 making 444hp and 516ft/lbs running the same boost levels.
So what plugs do VW specify for this modern turbo charged engine? The answer is VW first specified a Bosch FR6KPP332S, this plug has a centre electrode and earth electrode contracted from/plated in platinum.
But after two years of production VW switched to the one cooler NGK PFR7S8EG, this plug like the Bosch has a laser welded platinum tip center electrode and platinum on the ground electrode.
Clearly VW see absolutely no issue with using fine wire type plugs in a turbo charged engine but did choose to go one colder mid production, indeed if you study the NGK catalogue you'll see it's not just the turbo charged Mk7 Golf GTI using this type of plug, it's fitted to pretty much every turbo charged car...period!, when selecting a fine wire type plug for your turbo charged Rover V8 I would be tempted to follow VW's lead and switch to a cooler No7 plug. Platinum as a tip material offers improved longevity, but its worth noting Iridium is a step up from platinum, iridium tends to be more expensive than any other type of electrode material which is probably why VW went with platinum and chose a plug change service interval of 40,000 miles on the turbo charged Mk7 Golf GTI.
In addition to extending longevity, the other advantage of using these expensive rare metals is (for the same or greater strength) these type of electrodes can be made in a much smaller diameter, hence the generic term of 'fine wire', a smaller diameter and pointier electrode is always preferable. The only reason old generation traditional copper core plugs never had fine pointy electrodes like these new generation plugs do is plug manufactures simply didn't have the materials and more importantly the production technology to achieve it while still maintaining the strength and longevity required. Platinum and latterly iridium technology solved all this in a stroke as did the essential super fine and accurate laser welding technology needed to make the productionisation a reality.
If you look at a fine wire plug it's easy to see why people are scared off, its perfectly understandable that the assumption would be made that this type of spark plug has a weaker electrode than the big thick type we see on traditional old school copper core plugs, the truth however is that fine wire plug electrodes are actually more than twice as strong, even though the delicate appearance seems to suggest the complete opposite.
Interestingly the strongest most durable and best performing plugs on the market are those specified for use in engines that burn LPG, this is because LPG is a fuel that's much harder to strike than petrol, actually once LPG is burning it tends to do so in a slightly slower and more complete way. This longer push on the piston crown is why (with the right timing to suit the burn speed) we tend to see the same engine running on gas will always produce more torque at lower engine speeds than one burning petrol, this characteristic reveals itself as a smoother idle along with cleaner pulling away from junctions and better low speed maneuverability (reverse parking ect). Its no accident all spark plugs designed for engines burning difficult to strike LPG use fine wire technology, my NGK LPG plugs do so using an iridium central electrode with a chip of pure platinum on the earth electrode, they are effectively the best of both worlds but you do pay for this as a set of 8 are roughly £140
In summary if the OEM plug of choice for naturally aspirated and even turbo charged engines these days is more or less exclusively one using the fine wire type construction (in either platinum or iridium), I'd be confident in suggesting we should all consider moving to this type of plug in our much less stressed Rover V8s. I've been running fine wire plugs in my normally aspirated Rover V8 for years now, amusingly when I switched from the highly inappropriate shrouded NGK B7ECS chosen by TVR I was accused of knowing nothing and promoting snake oil, these attacks were of course ignored and complete nonsense, all I was doing was taking advantage of already proven technological developments made by the worlds most well respected plug manufactures including the mighty NGK, technology already universally adopted by the litigation phobic car makers themselves.
Running my TVR on these fine wire plugs the car immediately idled way better and was smoother pulling away from junctions, no real surprise if you consider how inappropriate the shrouded NGK B7ECS chosen by TVR were and still are, for the record the B7ECS is an endurance racing plug designed for the track, and a very old school technology one at that. The B7ECS really has no place on a low compression engine used in a road car as it'll never get hot enough to self clean, self cleaning being an essential requirement for the correct functioning of any spark plug.
To put this into something we can see on a forum, essentially I went from this....
To this...
Later on I switched to the NGK LPG range when I converted to gas, these being a more sophisticated (and way more expensive) version of the same fine wire technology iridiums I'd been using for years with fantastic results. For anyone considering a plug swap I'll repeat what I said and was ridiculed for all those years ago.... "Try a set of BPR6EIX iridium plugs in your naturally aspirated Rover V8, and tell me I'm wrong"
And for anyone running forced induction just follow VW's lead (and many others) of fitting the same fine wire technology to their turbo charged Mk7 Golf GTI, all you need to do is select one heat range cooler (a No7) and given all the evidence I think its fair to assume your blown Rover V8 will be just fine on fine wire plugs too.
The general answer is pretty much exclusively all manufactures have switched to a fine wire type plug, so to say this type of plug is unsuitable for old Rover (even a turbo charged Rover V8) is absolutely laughable.
Modern turbo charged engines are typically four cylinder and create a lot of heat, they put their spark plugs under way more stress than any Rover V8 would (even one running boost), however.... the heat range does remain as critical as ever, to reinforce this evidence lets look at the turbo charged Mk7 Golf GTI which is a good example to demonstrate my point.
The turbo charged Mk7 Golf GTI runs 14psi peak boost, the compression ratio of this modern four cylinder engine is 9.6:1, obviously the engine runs knock control pulling both timing and boost at the early onset of detonation, the engine is factory mapped to run 95Ron but VW do recommend premium grade fuel (97Ron in the UK) the engine management system will learn and adapt as it builds data, don't forget this engine in the US market must tolerate their 93Ron fuel all be it on a slightly different map.
This 2.0L inline four cylinder 16V turbocharged/intercooled engine makes 220hp at 4,700rpm and 258ft/lbs of torque at just 1,500rpm, 14psi spread over just 4 cylinders is a very different thing to 14psi shared across 8 cylinders, if we consider individual cylinder loads/pressures the turbo charged Mk7 Golf GTI must tolerate it would be the same as a V8 making 444hp and 516ft/lbs running the same boost levels.
So what plugs do VW specify for this modern turbo charged engine? The answer is VW first specified a Bosch FR6KPP332S, this plug has a centre electrode and earth electrode contracted from/plated in platinum.
But after two years of production VW switched to the one cooler NGK PFR7S8EG, this plug like the Bosch has a laser welded platinum tip center electrode and platinum on the ground electrode.
Clearly VW see absolutely no issue with using fine wire type plugs in a turbo charged engine but did choose to go one colder mid production, indeed if you study the NGK catalogue you'll see it's not just the turbo charged Mk7 Golf GTI using this type of plug, it's fitted to pretty much every turbo charged car...period!, when selecting a fine wire type plug for your turbo charged Rover V8 I would be tempted to follow VW's lead and switch to a cooler No7 plug. Platinum as a tip material offers improved longevity, but its worth noting Iridium is a step up from platinum, iridium tends to be more expensive than any other type of electrode material which is probably why VW went with platinum and chose a plug change service interval of 40,000 miles on the turbo charged Mk7 Golf GTI.
In addition to extending longevity, the other advantage of using these expensive rare metals is (for the same or greater strength) these type of electrodes can be made in a much smaller diameter, hence the generic term of 'fine wire', a smaller diameter and pointier electrode is always preferable. The only reason old generation traditional copper core plugs never had fine pointy electrodes like these new generation plugs do is plug manufactures simply didn't have the materials and more importantly the production technology to achieve it while still maintaining the strength and longevity required. Platinum and latterly iridium technology solved all this in a stroke as did the essential super fine and accurate laser welding technology needed to make the productionisation a reality.
If you look at a fine wire plug it's easy to see why people are scared off, its perfectly understandable that the assumption would be made that this type of spark plug has a weaker electrode than the big thick type we see on traditional old school copper core plugs, the truth however is that fine wire plug electrodes are actually more than twice as strong, even though the delicate appearance seems to suggest the complete opposite.
Interestingly the strongest most durable and best performing plugs on the market are those specified for use in engines that burn LPG, this is because LPG is a fuel that's much harder to strike than petrol, actually once LPG is burning it tends to do so in a slightly slower and more complete way. This longer push on the piston crown is why (with the right timing to suit the burn speed) we tend to see the same engine running on gas will always produce more torque at lower engine speeds than one burning petrol, this characteristic reveals itself as a smoother idle along with cleaner pulling away from junctions and better low speed maneuverability (reverse parking ect). Its no accident all spark plugs designed for engines burning difficult to strike LPG use fine wire technology, my NGK LPG plugs do so using an iridium central electrode with a chip of pure platinum on the earth electrode, they are effectively the best of both worlds but you do pay for this as a set of 8 are roughly £140
In summary if the OEM plug of choice for naturally aspirated and even turbo charged engines these days is more or less exclusively one using the fine wire type construction (in either platinum or iridium), I'd be confident in suggesting we should all consider moving to this type of plug in our much less stressed Rover V8s. I've been running fine wire plugs in my normally aspirated Rover V8 for years now, amusingly when I switched from the highly inappropriate shrouded NGK B7ECS chosen by TVR I was accused of knowing nothing and promoting snake oil, these attacks were of course ignored and complete nonsense, all I was doing was taking advantage of already proven technological developments made by the worlds most well respected plug manufactures including the mighty NGK, technology already universally adopted by the litigation phobic car makers themselves.
Running my TVR on these fine wire plugs the car immediately idled way better and was smoother pulling away from junctions, no real surprise if you consider how inappropriate the shrouded NGK B7ECS chosen by TVR were and still are, for the record the B7ECS is an endurance racing plug designed for the track, and a very old school technology one at that. The B7ECS really has no place on a low compression engine used in a road car as it'll never get hot enough to self clean, self cleaning being an essential requirement for the correct functioning of any spark plug.
To put this into something we can see on a forum, essentially I went from this....
To this...
Later on I switched to the NGK LPG range when I converted to gas, these being a more sophisticated (and way more expensive) version of the same fine wire technology iridiums I'd been using for years with fantastic results. For anyone considering a plug swap I'll repeat what I said and was ridiculed for all those years ago.... "Try a set of BPR6EIX iridium plugs in your naturally aspirated Rover V8, and tell me I'm wrong"
And for anyone running forced induction just follow VW's lead (and many others) of fitting the same fine wire technology to their turbo charged Mk7 Golf GTI, all you need to do is select one heat range cooler (a No7) and given all the evidence I think its fair to assume your blown Rover V8 will be just fine on fine wire plugs too.
Thanks Dave - fascinating and useful information.
So taking your conclusion, I should swap my BPR6EIXs for 7EIX, given that my turbo on my 4.6 is mapped for 7.5 psi.
I do take the point you made about the Golf GTi- my Saab 9-5 2.3 high output turbo (260 bhp from 2.3 litres) is running on 9s.
So taking your conclusion, I should swap my BPR6EIXs for 7EIX, given that my turbo on my 4.6 is mapped for 7.5 psi.
I do take the point you made about the Golf GTi- my Saab 9-5 2.3 high output turbo (260 bhp from 2.3 litres) is running on 9s.
Yes always good to get another take on it.
My concern was any risk going to a hotter rated iridium plug when TVR specced 7's non projected as standard and then with me running up to 9/10psi as I didn't want them coking up. However as they operate far more efficiently they should in theory keep even cleaner, I also removed my BPR7ES plugs and they are pretty good colour with minimal deposits, so the heat rating (at least on mine) as it stands seems perfect on a 7 which sits your argument about right Dave.
IMO and experience when running projected 6 plugs on a NA RV8 there is little to worry about, I've had no issues and the plug burn has been spot on.
I do understand people's reservations though especially when big engine building money has been spent and the advice given is very cautious, you know are the gains worth the risk.
Anyway before I checked back in to write this I've ordered some BPR7EIX plugs from car parts for less on a next day, give or take they are about as cheap as your going to get them if you want them quick. ECP's who I think are under the same umbrella wanted another 35 quid.
My concern was any risk going to a hotter rated iridium plug when TVR specced 7's non projected as standard and then with me running up to 9/10psi as I didn't want them coking up. However as they operate far more efficiently they should in theory keep even cleaner, I also removed my BPR7ES plugs and they are pretty good colour with minimal deposits, so the heat rating (at least on mine) as it stands seems perfect on a 7 which sits your argument about right Dave.
IMO and experience when running projected 6 plugs on a NA RV8 there is little to worry about, I've had no issues and the plug burn has been spot on.
I do understand people's reservations though especially when big engine building money has been spent and the advice given is very cautious, you know are the gains worth the risk.
Anyway before I checked back in to write this I've ordered some BPR7EIX plugs from car parts for less on a next day, give or take they are about as cheap as your going to get them if you want them quick. ECP's who I think are under the same umbrella wanted another 35 quid.
Edited by PhilH42 on Wednesday 13th September 13:25
Strewth - just been on hold for half an hour trying to get a price off them, as their website is car registration fixated and says they cannot supply spark plugs for my car.
Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
QBee said:
Strewth - just been on hold for half an hour trying to get a price off them, as their website is car registration fixated and says they cannot supply spark plugs for my car.
Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
Haha what happened to the days of going to pick up and pay in cash hey?!Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
Just internet search the plug ngk bpr7eix Anthony and then press on carparts4less picture icon. Then specify the 8 and its in the basket and pay online £62 quid ish....I did the same going to the site and its a cock up with the reg thing.
Then you can thank me when you only get the 4
QBee said:
Strewth - just been on hold for half an hour trying to get a price off them, as their website is car registration fixated and says they cannot supply spark plugs for my car.
Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
Euro Car Parts; use the registration number E626 DJX. This will give you BPR7EIX on their website.Of course, if I had realised that NGK BPR7EIX was actually 408510031 in Carnetbearsed4less.co.uk speak, it would have been quicker.
Given up, I will buy mine elsewhere
(fits Aston Martin V8 1987 with a compression ratio of 9.3:1)
Currently you can use 'save30' for a price reduction so they are £8.39 each. Don't seem to be in stock though so 48 hour wait.
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